Consistent with the results in cells, the Western blotting analysis demonstrated KNK437 reversed the downregulations of p‐ERK1/2 and p‐JNK1/2 and the upregulation of HSPA1A in T‐BPH rats to varying degrees (Figure 8E,F), implicating that inhibition of HSPA1A probably ameliorated prostatic hyperplasia through the ERK/JNK pathway. Here, MAPK8 is linked to benign prostatic hyperplasia.